Optical and Electrical Hybrid Connector

ABSTRACT

An improved hybrid connector for rapidly, reliably, and reversibly making mixed optical and electrical connections has a male plug with one or more centrally located optical fibers centrally located inside an elongated shaft of a male plug, and one or more electrical contact elements are located on the peripheral surface of the shaft, and a socket with electrical contacts, and a floating optical connector. Insertion of the elongated shaft into the socket connects the electrical contacts of the shaft and socket and couples the fibers of the shaft with optical fibers in the floating optical connector.

RELATED APPLICATION

This application claims priority to Provisional Patent Application Ser.No. 60/580,414, filed on Jun. 16, 2004, the disclosure of which ishereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to plug and socket connector systems forproviding inexpensive, reversible, axial-position-error tolerant(Z-tolerant) mixed optical and electrical connections, and moreparticularly to a quick-insertion, non-shorting, rotationally engaged,shaft and socket connector having one or more Z-tolerant float-coupledoptical fibers located centrally inside an elongated shaft, and one ormore Z-tolerant wide electrical contact array elements located on aflexible PC board mounted peripherally on the same shaft, for thepurpose of creating reversible optical/electrical hybrid connections,thus avoiding much of the expense, awkwardness, and required axialprecision inherent in conventional hybrid connector systems.

BACKGROUND OF THE INVENTION

The traditional optical or electrical connector is a monolithic device,optimized for the delivery of a single signal type—either optical orelectrical. There are reasons for this traditional separation ofconnectors by signal type. First, most applications require only onetype of transmitted signal, and thus do not demand the additional designand materials expense involved in hybrid connections. Second, inherentfeatures required for good electrical connections (e.g., good physicalcontact with contact element wiping, low axial positional matingaccuracy, and no need of contact finishing after assembly) aredifferent, and often contrary, to those features required for goodoptical fiber coupling (avoiding physical contact which damages fiberfaces, high axial positional mating accuracy, and required post-assemblyfiber-end finishing steps).

These limitations and requirements are best appreciated by examining thesource of such differences between optical and electrical connectionsduring mating and assembly.

First, consider the presence or avoidance of physical contact duringmating. Electrical connections generally require good physical contactin order to achieve reliable, low-resistance current flow. Metalliccontacts also tend to accumulate surface deposits and corrosion overtime, so a “wiper” effect is usually incorporated into the physicalmake-and-break actions to facilitate ongoing contact cleaning. Incontrast, good physical contact between optical fibers is generally tobe discouraged because the layered glass faces of fibers are fragile.Direct physical contact between optical fibers damages the cladding thatkeeps light within the fibers, scratches the optical fiber face wherelight is transmitted, or shatters the fiber body entirely, all of whichreduce fiber light transmission or renders the fiber useless.

Next, consider the axial (Z-axis) positional accuracy required duringmating. Electrical pin and socket connections, once inserted part way,usually continue to work well as the elements are pushed farthertogether. In fact, a bit of additional insertion in electrical contactsusually leads to improved contact due to the increased contact surfacearea and wiping effects. Therefore, there is little Z-axis positionalaccuracy typically required to make an electrical connection work well.This permits electrical contacts to be manufactured cheaply in largearrays using low-axial-accuracy metal pins and sockets, such as thestandard D-pin connectors used in the computer industry which have 9 to100's of pins in a planar (flat XY-axis plane perpendicular to the axisof insertion) arrangement. Such planar electrical contacts typicallyalso have lateral pin wiggle—easily demonstrated in a 9-pin standardD-Pin connector in which the male pins each show millimeter lateralmovement if physically perturbed.

In contrast, optical connectors are not so tolerant of error. Fiberconnections have lateral (XY-axis) and axial (Z-axis) positional matingaccuracy requirement as much as 1,000-fold more precise than for theabove-described electrical connections. An optical fiber's tolerance forpositional error is typically very low for several inherent reasons.First, axial (Z-axis) movement of optical fibers away from each otherresults in a loss of optical coupling; while axial movement toward eachother must be carefully limited into order to prevent collisions betweenthe fiber ends. Such collisions can seriously damage most optical fiberfaces. Second, a seemingly minor lateral positional misalignment of apair of optical fibers typically leads to huge fiber coupling losses.For illustration, a mere 0.004 inch lateral offset between a 100 micronpair of multimode fibers can lead to a complete loss of transmittedlight.

Because of this need for micron alignment between coupled opticalfibers, fiber connections typically require high-precision components inthe connector. These precision components—including laser drilledferrules and milled stainless-steel couplers—translate to a highconnector cost. For example, a pair of industry-standard SMA-typeoptical plugs and central mating dual-female coupler connector, allowingfor the joining of only a single pair of fibers, retails at many timesthe price of a pair of 25-pin D-type electrical array male/femaleconnectors.

Third, one must consider the accessibility of the contacts duringassembly and finishing. Electrical pins are typically shielded orhooded, and the sockets recessed, to prevent wire to wire shorting. Incontrast, optical fiber ferrules must typically protrude beyond anyprotective holders in order to allow for fiber finishing (such asgluing, sanding, and polishing) after a new, bare optical connector isstuffed and glued with an optical fiber.

All told, when taking into consideration the above inherent limitations,electrical and optical connectors have physical contact, positionalaccuracy, and post-assembly requirements that come directly intoconflict, and such conflicting requirements are not readilysimultaneously satisfied.

The above limitations of conventional connectors are apparent in theart.

Hybrid optical and electrical connectors are known. Such deployments aremost typically planar (XY-axis), in which the mating elements form aface that is flat and perpendicular to the axial mating axis. Forexample, WO 01/042839 and U.S. Pat. No. 6,612,857 teach independentdetachable electrical or optical assemblies that are combined into asingle hybrid connector. U.S. Pat. No. 6,599,025 teaches a hybrid withthe optical fiber positioned between the electrical elements of astandard connector. U.S. Pat. No. 6,588,938 teaches a hybrid housingwith planar arrays of electrical contact maintained by springs. Anindependent element hybrid commercial product is known (Miniature F7Contact for Multi and Hybrid Fibre Optic Connectors, Lemo, Switzerland).These Lemo connectors, by failing to simultaneously optimize thedifferent requirements of optical and electrical connections throughZ-tolerance, remain expensive (greater than US $100 per connector). Allof these hybrid devices remain simple, non-optimized devices that sufferfrom the drawback that they use independent, standard, planar couplingelements without optimization of the differing and conflictingelectrical and optical mating requirements, and do not suggest or teacha need for increased axial tolerance, all of which is required forlow-cost simultaneous mating of both the electrical and optical signals.

Axial (Z-axis) deployment of the electrical contacts along a shaft is aknown, though uncommon, alternative to planar contact deployment. U.S.Pat. No. 4,080,040 teaches a longitudinal (axial) arrangement ofmultiple electrical contact elements along a patch-cord plug andreceiving jack, but does not teach how to reduce the axial positionalaccuracy requirements of the connector through use of floating orlens-coupled elements for fibers in a hybrid design. Combination of thisor other axial plug and socket arrangements with optical fibers, as istaught in the cited hybrid connectors above, would be insufficient toachieve Z-tolerance, as a need for Z-tolerant elements to increase axialtolerance is neither taught nor suggested in either body of art.

Optical elements facilitating good fiber coupling along with reducedaxial mating accuracy are known. U.S. Pat. No. 5,259,052 teaches alimited-movement floating ferrule that is used to couple two fiber opticplugs. U.S. Pat. No. 6,550,979 teaches a spring-coupled ferrule whichurges the ferrule holder in a direction axially toward the mated fiber.However, these are free standing optical elements, without considerationof the design requirements of simultaneous electrical connections, andtherefore combination with known hybrid designs is non-trivial. Thesefloating device elements neither teaches nor suggests combining afloating optical element into a hybrid electrical/optical connector thatsimultaneously optimizes both electrical and optical mating in thepresence of the floating elements, a non-trivial manufacturing step.

Each of the above connector systems and methods suffer from one or morelimitations noted above, in that they do they do not incorporateZ-tolerance into both optical and electrical connecting elements (e.g.,do not incorporate improved axial tolerance at all, or are not combinedinto a single, integrated connector that simultaneously optimizes themating requirements of both the optical and electrical connections),which makes manufacturing and assembly of a hybrid connector technicallydifficult or expensive.

None of the above systems suggest or teach efficiently combining opticaland electrical contacts into a single hybrid connector device optimizedfor both electrical and optical connections with both (a) a Z-tolerantcoupling for the optical elements, and (b) a Z-tolerant coupling for anaxial electrical array, together resulting in a low-cost of manufacture,ease of assembly, and single connector ease-of-use. A hybrid electricaland optical shaft and socket connector incorporating a Z-tolerant axialelectrical array integrated with a Z-tolerant floating or lens-coupledfiber array has not been taught or suggested, nor to our knowledge hassuch a tool been previously successfully manufactured andcommercialized.

SUMMARY AND OBJECTS OF THE INVENTION

The present invention relies upon the knowledge of design considerationsneeded to achieve a hybrid plug and socket connector with a Z-tolerantcentral floating optical fiber coupler and a Z-tolerant axialcircumferential electrical contact array, allowing for rapid,inexpensive, axial-position-tolerant, self-wiping, reliable connectionsbetween connector elements, so as to provide an improved connection. Thebenefits include rapid connection, rapid disconnection, low-cost,disposability, reproducibility, and reliability. This allows theimplementation of medical monitors and probes more simply andinexpensively than has been achieved using commercially availableconnectors.

A salient feature of the present invention is that, while bothelectrical and optical connectors have different positional-accuracymating requirements, the use of a Z-tolerant, axially deployed, widecontact, peripheral electrical contact array and a Z-tolerant floatingcentral fiber core allows the differing mating requirements to bereliably and simultaneously satisfied. The floating optical core fiberis self-aligning, self-centering, axially-position-tolerant, and highlystable and reproducible. The floating component takes up Z-axispositional inaccuracies while maintaining absolute control over thedistance between the coupled fiber faces. More than one fiber can beused. At the same time, the linear electrical array allows broad,self-wiping, non-shorting, physical contact areas which are themselvesZ-tolerant, without the high-mating-requirements typically demanded byoptical matings. This substantially lowers the cost of the electricalconnectors, while maintaining expandability of 1 to N non-shortingquick-connect contacts. Further, such wide contacts can be molded orprovided by a flexible PC board very inexpensively, making the entireconnector, and in particular the plug portion, manufacturable at verylow cost.

Accordingly, an object of the present invention is to provide aZ-tolerant hybrid connector using a wide electrical contact arrayperipherally and circumferentially deployed around a central fiber core,which is itself Z-tolerant due to lens or float coupling. In itssimplest from, the fiber core has only one fiber coupled using an axialfloating coupler, and at least two wide peripheral electrical contacts,but this may be expanded to add additional optical fibers and electricalcontacts as needed. Similarly, some of the electrical contacts may bereplaced or supplemented by non-contact ID chips that do not require adirect connection.

Another object to provide a non-shorting electrical contact array withgood physical contact that is engaged and wiped by rotation of the plugafter insertion into the socket, enabling use with sensitive electronicsor high-power applications.

Another object is to provide for a high-precision stabilization of theoptical connections, which are stabilized by a locking action withrotation of the plug shaft.

Another object is to provide for a reversible quick-connection, withconnection occurring in less than 1 full turn of a plug shaft, andpreferably latching in one-fourth clockwise turn. This in turn allowsfor natural quick attachment and for quick disconnection, withdisconnection occurring again in less than 1 full turn of the shaft, andpreferably in one-fourth counterclockwise turn.

Another object is to provide for probes and systems with integratedconnector systems, allowing for improved medical spectroscopic devices.

A final object is to provide for a connector with embeddedidentification and data, such as probe type, for example via EEPROMaccessible across the connectors electrical connections, or even bynon-contact ID functions, such as the RF chips used in proximity IDtags.

The improved hybrid connector as described has multiple advantages.

One advantage is that devices with both electrical and opticalconnections can be quickly attached using a single connector.

Another advantage is that a centered fiber with coupling ferrule orcoupling channel is self-aligning, and allows incorporation ofZ-tolerant optical coupling techniques, such as transfer or collimatinglenses and elements, floating couplers, and the like.

Another advantage is that this attachment can occur reversibly, rapidly,and reliably.

Another advantage is that the costly parts (the precision, floatingalignment tube into which a shaft ferrule fits or a reverse collimatinglens) can be placed into the socket connector, while the male plug shafthas only printed-circuit or card edge contacts, and low-toleranceoptical ferrules, which are inexpensive compared to individualelectrical contacts and precision optical connectors.

A further advantage is that the electrical connection can be expanded asto any number of contacts, simply by increasing the length of theinserted shaft, reducing the spacing of the contacts, or addingadditional parallel electrical array contact rows.

There is provided a Z-tolerant hybrid connector for providing areliable, rapid, unified, and reversible connection for mixed electricaland optical connections, specifically in the examples shown for thepurpose of enabling spectroscopic analysis in human patients in realtime. In one example, the Z-tolerant connector uses an axial plug with asemi-circumferential-element linear electrical contact array deployedaxially along its long axis, with central fiber and optical connectionelements. A floating axial positionally tolerant floating coupler allowsthe fiber coupling to maintain a high internal axial accuracy with aninexpensive low axial-accuracy plug shaft. The plug mates reversibly toa socket containing a keyed channel into which the plug's shaft is fullyinserted and then rotated. A turn of the plug shaft mates the electricalpads on the plug shaft with the spring contacts in the hollow channel ofthe socket, as well as stabilizing and securing the plug. Removal isachieved by rotation in the opposite direction, breaking the electricalcontacts and allowing the plug to be removed from the hollow channel.Medical probes and systems incorporating the improved connector are alsodescribed.

These and other advantages of the invention will become apparent whenviewed in light of the accompanying drawings, examples, and detaileddescription. The breadth of uses and advantages of the present inventionare best understood by the detailed explanation of the workings of ahybrid connector, now constructed and tested in laboratory and clinicalmedical monitors.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the followingdescription in connection with the accompanying drawings of which:

FIG. 1A is an exploded perspective view of a plug and socket inaccordance with the present invention;

FIG. 1B is an enlarged view of the spring loaded contacts in the socketof FIG. 1A;

FIG. 2 is a perspective view of the plug;

FIG. 3A is a perspective view partly in section showing the plug as itis inserted and seated into the socket;

FIG. 3B is an enlarged view of a portion of the inserted plug and socketof FIG. 3A;

FIG. 4 is a front view of the plug;

FIG. 5 is a side view of the plug showing the guiding and lockingchannel;

FIG. 6 is a plan view of the socket;

FIG. 7 is a rear view of the socket;

FIG. 8 is a plan view of the socket showing the contact pins;

FIGS. 9A and 9B are sectional perspective views illustrating insertionand rotation of the plug;

FIG. 10 is a sectional view showing the plug inserted into the socket;

FIG. 11 shows a medical probe incorporating the Z-tolerant hybridconnector of FIGS. 1-10;

FIG. 12 shows a medical monitor incorporating the Z-tolerant hybridconnector of FIGS. 1-10 to which the probe of FIG. 11 is attached toform a complete medical system;

FIG. 13A is a graph showing a plateau of Z-tolerant connections theability using a floating optical connection designed in accordance withthe present invention;

FIG. 13B is a graph showing a plateau of Z-tolerant connections theability using a coupling lens element designed in accordance with theinvention.

DEFINITIONS

For the purposes of this invention, the following definitions areprovided:

Hybrid Connector. A connector that contain both optical and electricaltransmission lines to be coupled. Also called a Mixed Connector.

Plug: The elongated, shaft-like member of the connector. Also called aMale Plug or Shaft.

Socket: The hollow, receiving-chamber member of the connector, to whichthe Plug member is coupled by insertion of the plug into the receptacle.Also called a Female Socket, Receptacle, or Chamber.

Peripheral: Located on or near the outer surface of the plug shaft, orthe along the inner chamber surface of the socket receptacle. Examplesof peripheral contacts include an array of electrical pad elementslocated on the surface of a rod-shaped plug, or a card edge located nearthe surface of a rod-shaped plug (c.f. central).

Central: Located at the inner or central region, not peripherally. Forthe shaft of a plug, the core is toward the center of the shaft; for asocket, the core is located toward the axial central portion of thespace in the socket chamber (c.f. peripheral).

Axial: Along the long axis of an elongated member or connector insertionpath. Also called the Z-Axis (c.f., planar).

Planar: Located perpendicular to the long axis of an elongated member orconnector insertion path.

Z-Tolerant or Axially Position-Tolerant: An element for which properoperation or coupling is not highly dependent upon an exact position ofthe inserted plug relative to receptacle socket in the axial (Z-axis)direction.

Axial Array: A set of at least two contact elements deployed axially,for example a linear row of electrical contact pads are each deployedcircumferentially at different fixed distances along the length of theshaft of a plug (c.f., planar array, below).

Planar or X-Y Array: A set of at least two contact elements deployed ina plane perpendicular to the insertable plug face.

Circumferential: Following the circumferential curve of a rod, shaft, orchamber, while keeping, more or less, the same linear distance from theend of the rod, shaft, or chamber. A circumferential element may be acircular ring (fully circumferential), or an open ring or short arc(semi-circumferential). A semi-circumferential ring, pad, or arc shapedelement only partially encircles the rod, shaft, or chamber.

Rotationally Engaged: A connector that is rotated in order to lock theprobe and/or engage one or more sets of contacts.

Optical Coupling: The arrangement of two optical elements such thatlight exiting the first element interacts, at least in part, with thesecond optical element. This may be free-space (unaided) transmissionthrough air or space, or may require use of intervening, fixed orfloating, optical elements such as lenses, filters, fused fiberexpanders, collimators, concentrators, collectors, optical fibers,prisms, mirrors, or mirrored surfaces.

Electrical Coupling: The arrangement of two electrical elements suchthat the two elements can electrically interact and, in most cases,useable current can flow between them.

Floating Coupler: A Z-tolerant optical coupling element. In one example,the Z-tolerant optical coupling element is a spring-loaded floatingcoupler that physically moves axially to allow for a high-precisioncoupling of two or more optical fibers, while allowing for tolerance ofsignificant variance in the axial position of one fiber to the other,thus enabling a quality optical coupling that is tolerant of axialpositional error without the risk of poor optical coupling due toexcessive fiber face to fiber face distance, or of damaging the coupledfiber faces due to insufficient fiber face to fiber face distance. Inanother example, the Z-tolerant optical element is a set of collimatinglenses that have a relative insensitivity to the distance between thelens elements, allowing for Z-tolerance in the distance between thecoupled fibers to be of low importance to the quality of the opticalconnection.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to FIG. 1A, the connector includes a male plug 11 having anaxial shaft 13 and is shown disengaged from female socket assembly 14.The shaft 13 contains an axial central optical fiber which terminates ina ferrule 16. The shaft may accommodate multiple optical fibers. Theferrule 16 is just one example of an optical coupling element, and otherequivalent elements would work provided they result in optical couplingacross the connector. In FIG. 1A, a circuit board 17 is shown detachedfrom the socket. The circuit board includes a plurality of spring loadedcontact elements 18 shown in enlarged view in FIG. 1B which project intothe socket through the slot 21 shown in dotted line. It is apparent thatthe contact elements may form a part of the socket.

FIG. 2 is a perspective view of the male plug 11 rotated to show aplurality of electrical contacts 22 which extend from the flat surface23 onto rounded portion of the shaft for electrical contact with thecontact elements 18. The number of contacts depend upon the electricalrequirements of the electro-optical device with which the plug isassociated. The electrical contacts 22 may be plated copper pads on aflexible circuit board that is adhered to the shaft. The contacts aremounted along flat portion 23 of the shaft and extend onto the roundedportion of the shaft. The contacts have axially extending leads 25. Suchuse of flexible printed circuit contacts facilitates the rapid massproduction after injection molding of the plug or shaft and furtherallows direct connection to integrated circuits which may be embedded inthe connector such as an EEPROM memory 24.

Referring to FIGS. 1A, 1B, 3A, 3B and 5, the shaft has an L-shapedalignment channel 26 diametrically opposite the flat surface 23 of theplug. The socket includes a pin 28, FIG. 1A and FIG. 3A, which engagesthe alignment channel as the shaft is inserted into the socket asillustrated in FIG. 3A. The axial movement of the shaft is stopped whenthe pin engages the circumferential or arm portion 29 of the groove. Theshaft is then rotated so that the pin travels into the perpendicularextending portion of the groove 29 until it is fully engaged. As theshaft is inserted, the contact elements 22 on the flat portion of theshaft do not engage the spring loaded contacts 18. After the shaft isinserted and rotated, the portion of the contacts extending onto therounded portion are brought into sliding engagement with the contactelements to provide a sliding contact. Thus the electrical connectionportion of the connector has been described.

Turning now to FIGS. 6-10 the optical coupling portion of the connectoris described. The socket 14 includes a bore 31 which is enlarged 32 atits distal end to terminate in shoulder 33. The enlarged bore receives afloating spring loaded optical coupling element 34 which has a portionof reduced diameter 35 to receive a spring 36. An end plate 37 issecured to the end of the socket by, for example screws 35, and engagesthe other end of the spring 36 to urge the coupling element in the axialdirection so that it abuts the shoulder 33. Optical cable such as cable38 with optical fibers, such as fiber 39 extends into the couplingelement a predetermined distance. The end of the cable may be polishedto present the optical fiber at its face 40. When the plug is insertedinto the socket the coupling element receives the ferrule at the end ofthe plug and centers and guides the ferrule until the shoulder 41 at theend of the plug engages the end of the coupling element. At this pointthe end face of the ferrule 16 and the face of the optical cable areaccurately spaced and positioned with respect to one another for goodoptical coupling without physical contact. The plug can then be rotatedfor providing the sliding electrical contact described above.

Thus the coupling element is adapted to receive the ferrule when theplug is inserted into the socket and the distance between the end of theferrule fibers and the end of the coupler fibers are closely spaced toone another to provide the optical coupling. As a result there isone-to-one alignment of the optical fibers as the electrical contact ismade and the plug is inserted into the socket.

Connector plug 13 can optionally be embedded within a medical device, asshown with plug 13 embedded in medical catheter probe 203 (FIG. 11).Probe 203 has patient-end 206, catheter body 207, and monitor-end 208.In probe 203, flexible body 207 consists of a section of US FDA class VIheat shrinkable tubing 214 surrounding medical grade Tygon™ tubing 217,both of which are further swaged to light illuminator 218 at swagepoints 219 near probe patient end 206. Wires 222 and 223, fromelectrical contacts 22 of plug 13 (as shown in FIGS. 3A, 3B) travelthrough concentric tube 214 and 217 and terminate by connecting to theleads 25 of plug 13 at monitor end 208. Optical connection fiber 224from illuminator 218 travels from the patient tip of probe 203, runningparallel with wires 223 and 224 inside concentric tubes 214 and 217, toterminate in ferrule 16 of monitor-end plug 13. Plug 13 is a reversiblehybrid connector plug containing the electrical and optical connectionsdescribed above.

Probe 203 may be “smart” with optional memory chip 24 integrated intoprobe body 13. This chip may retains information useful in the operationof the device, such as calibration parameters, a reference database, alibrary of characteristic discriminant features from previouslyidentified tissues, and so on, and this information may be accessiblevia plug 13. Additionally, information on chip 24 may include probeidentification, probe serial number, use history, calibration details,or other information accessible through plug 13.

The hybrid connector 11 may be incorporated into a medical system, suchas medical system 267, FIG. 12 with probe attached to system 267 viaplug 13 and socket 14. Examples of such a spectroscopic monitoringsystem and monitoring probe are disclosed in WO 03/086173.

Operation and use of the connector is now described. In this example,connector plug 13 is incorporated into medical catheter probe 203, andconnected to spectroscopic monitoring device 267 via socket 14, as shownin FIG. 12.

Referring again to FIGS. 3A, 3B, Plug 13 is first inserted into socket14. To accomplish this, the plug 13 is held in axial alignment with thesocket 14. Probe shaft 13 is then inserted into socket 14 after aligningpin 28 of socket 14 mates with slot 26 of plug 13. This movement isillustrated by axial insertion/removal arrows 42. Connector plug 13, andferrule 16 are pushed with zero to low insertion force until they arefully inserted.

A key step now occurs. Ferrule 16 of plug 13 is automatically alignedas, and it mates with coupler 33 a few millimeters before ferrule 16 isfully inserted. The faces of the optical fiber to be coupled wouldlikely be either damaged due to contact collision, or the faces would betoo far separated to be efficiently coupled. However, in thisembodiment, coupler 33 is a floating connector, held as forward asallowed in the design toward the insertion (entry) end of socket 14 byspring 36. As ferrule 16 reaches full insertion in coupler 33, the fiberfaces are allowed to continue to remain within microns of each other,without collision, and while ferrule 16 is fully inserted into, coupler33. The coupler moves to absorb the further and final forward movementof ferrule 16. This movement allows pin 28 of socket 14 to be fullyinserted along slot 29 of plug 13, bringing ferrule 16 into effectiveoptical contact. The electrical contacts 22 are now in axial but notrotational alignment with socket electrical contact array 22. Thus,contact array 22 and socket array 18 remain out of electrical contact atthis time.

Finally, plug 13 is rotated ¼ turn clockwise in socket 14, a movementnot permitted during the initial axial insertion into socket 14 becausethe channel 26 permits only axial in-out movement. However, once plug 13is fully inserted into socket 14, rotation is permitted because pin 28can now turn into partially-circumferential short arm 29 of channel 26,as shown in FIG. 3. Once pin 28 has rotated to the distal end ofshort-arm 29, plug 13 is fully rotated and cannot rotate further in thesame direction. The rotation of plug 13 after axial insertion performsat least three functions. First, pin 28 is now in the distal portion ofshort arm 29 of channel 26, securing and locking plug 13 in place andpreventing axial displacement or removal of plug 13 from socket 14.Second, ferrule 16 is held with pressure in continued optical alignmentin connector 33, maintaining proper optical fiber alignment and spacingdespite probe movement in, then slightly out, in the Z-axis axialdirection. Third, contact array 22 is held in sustained electricalcontact with socket array 18.

Some probes may also require an illumination fiber, or other additionalfiber channels, without critical alignment requirements. Such can useother optical ferrules added to the probe. In some cases, theseadditional fibers may not be as alignment critical.

In some cases, memory chip 24 can be added to the connector, ormemory-read circuitry can be added to the socket as well, or vice-versa.

Last, additional non-contact connections can broaden utility. Forexample, a “passive” radio-frequency identifier chip can perform thehandshaking function with an internal memory chip, allowing a circuit inthe female side to query and read a chip on the male side. Similareffects can be accomplished with an active transmitter on the male side,using known wireless linking technologies known in the art. In fact, thepower for the illuminator could even be transmitted, as non-contactpower transmission technologies are now also known.

EXAMPLES

Operation of the device is demonstrated in the following examples,constructed using a shaft and socket connection constructed inaccordance with the present invention.

Example 1

A working version of the optical and electrical hybrid connector wasconstructed. Light throughput was recorded in using an EXFO opticalpower meter (Exfo, Quebec, Canada) through 100 micron glass/glassoptical fiber (FV100/101/125 silica clad fiber, Polymicro Technologies,Phoenix Ariz.) as the shaft plug is inserted in the receptacle socket.Axial displacement relative to the final, fully inserted position wasrecorded at intervals of 1 mm over the final 1 cm of insertion.Referring now to FIG. 13A, the recorded optical power values wereplotted as line 312, which is a function of relative optical throughputvs. distance from the fully inserted connector position. There is notedplateau region 317 spanning the final 2 mm of insertion, in which theintensity of transmitted light does not fall by more than 12%,demonstrating (by definition) an axial-position tolerance.

The above experiment was then repeated using the same shaft and socketsystem, but in this case with optical coupler 33 and spring element 36secured such that the floating action was completely ablated. Referringagain to FIG. 13A, the recorded optical power values were plotted asline 319. There is no stable plateau region in transmitted intensityline 319 with shaft axial position—even a 1 mm displacement results in50% signal loss—showing that without the floating element, Z-toleranceis lost.

The relevance of the above experiment is that the manufacturing of ametal or plastic shaft with millimeter tolerance (i.e., ±1 mm), theaxial tolerance is well handled by the Z-tolerant floating connectordesign. In contrast, the non-floating system does not exhibitZ-tolerance, and therefore requires micron manufacturing tolerances(e.g., 0.02 mm, or ±20 microns). The high precision required in thenon-Z-tolerant connector necessitates significantly more precise andcostly stainless steel molds and/or laser drilled components. In ourexperience with reducing the above design to manufacturability, aZ-tolerant shaft plug can be produced for about one-fifth the cost ofthe non-tolerant shaft in similar volumes.

Example 2

An optical and electrical hybrid connector was constructed where opticalcoupler was an SMA optical coupler/connector with integrated reversedbeam expander optics (Model F230SMA-A collimator, Thorlabs, Newton,N.J.), and further, spring 36 was omitted such that the physicalfloating action of coupler 33 was completely eliminated. The design,however, remains Z-tolerant, as the collimating lens provideslens-coupled axial-position-tolerance.

As before, light throughput was recorded using an optical power meterthrough 100 micron glass/glass optical fiber as the probe was insertedinto the connector. Axial displacement from the final, fully insertedposition was recorded at intervals of 1 mm over the final 1 cm ofinsertion. Referring now to FIG. 13B, the recorded optical power valueswere plotted as line 322, which is a function of relative opticalthroughput vs. distance from the fully inserted connector position.There is noted plateau region 327 spanning the final 5 mm of insertion,in which the intensity of transmitted light does not fall by more than20%, demonstrating (by definition) an axial-position tolerance. In thiscase, the Z-tolerance comes not from a floating element as in Example 1,but rather from the lens-coupled collimator that increases theZ-tolerance of the optical coupling.

The above experiment was then repeated using the same shaft and socketsystem, but in this case with the non-floating optical coupler fromExample 1, above, in place of lens-coupled optical coupler of the aboveparagraph. This is identical to the setup of the non-Z-tolerantexperimental set up of Example 1. Referring again to FIG. 13 there is noplateau region in transmitted intensity line 329 with changes in shaftaxial position, showing that without the lens-coupled element,Z-tolerance once again no longer exists.

Other methods of hybrid connection Z-tolerance may be envisioned,including the combination of lens- and float-coupled optical elements,or alternative methods readily apparent to one skilled in the art. Theexamples of lens- and float-coupled elements are provided merely asexamples, and are not intended to be limiting with respect to thepresent invention.

In summary, an improved hybrid connector can result from an axialposition-tolerant hybrid connector with a central fiber set, peripheralaxial electrical connector array, and a Z-tolerant optical andelectrical connection. In certain applications, such as medicalapplications, this allows for single-connector, quick-connect,quick-disconnect, self-aligning, low-insertion-force probes with anon-board memory chip identifying the probe. Such improved connectorspermit hybrid connections to be easily added into a medical probe,catheter, or monitor system.

We have discovered an improved Z-tolerant hybrid optical and electricalconnector for making reversible, for single-connector, quick-connect,quick-disconnect, self-aligning, hybrid connections. Such a connectorhas been constructed and tested, and incorporated into a medicalcatheter, all constructed in accordance with the present invention to afunctional hybrid connector. An EEPROM within the shaft allows fortracking, identification, and calibration of the probe. Medical probesand systems incorporating the improved illuminator, and medical methodsof use, are described. This device has been built and tested in severalconfigurations, and has immediate application to several importantproblems, both medical and industrial, and thus constitutes an importantadvance in the art.

1-9. (canceled)
 10. A medical illuminator catheter comprising: (a) abiocompatible catheter sheath, said catheter sheath having a monitorend, a central body, and a patient end; (b) an optical and electricalhybrid male plug located at the monitor end of said catheter; (c) alight source at the patient end of said catheter; (d) at least oneoptical collection fiber for collecting light scattered from a regionilluminated by the light source and for transmitting said collectedlight from said patient end of the catheter, along a length of saidcatheter and into said male plug at the monitor end of the catheter; and(e) power supply wires for transmitting electrical power to said lightsource, said wires traversing a length of said catheter and electricallyconnected to both said light source and to contacts on said connectionplug. 11-21. (canceled)
 22. A medical illuminator catheter comprising:(a) a biocompatible catheter sheath, said catheter sheath having amonitor end, a central body, and a patient end; (b) a plug located atthe monitor end of said catheter for connecting the catheter to amonitor, a cable functionally connected to a monitoring system, orwireless connection to a wireless network; (c) a light source at thepatient end of said catheter; (d) at least one optical collection fiberor optical element for collecting light scattered from a regionilluminated by the light source and for transmitting said collectedlight or a signal derived from said collected light, from said patientend of the catheter, along at least a portion of a length of saidcatheter and into at least one of said male plug at the monitor end ofthe catheter, light detector, or spectrometer; and, (e) power supplywires for transmitting electrical power to said light source, said wirestraversing a length of said catheter and electrically connected to bothsaid light source and to contacts on said connection plug.
 23. Thecatheter of claim 24, further comprising a memory information chipconfigured for retaining information useful in the operation of thedevice.
 24. The catheter of claim 24 wherein the catheter furthercomprises a socket and wherein further said socket has an alignment pin,said shaft has an L-shaped channel for receiving said alignment pin andpreventing rotation of said shaft during axial insertion into saidsocket, said shaft having a flat region with said peripheral electricalcontact elements further arranged so as not to make electrical contactwith said socket contacts during said axial insertion and furtherarranged so as to make electrical contact with said socket electricalcontacts after the shaft is fully inserted and rotated when the pin isat the end of the elongated channel.
 25. The catheter of claim 24wherein the catheter is configured to function as an oximeter probe. 26.The catheter of claim 10, further comprising a memory information chipconfigured for retaining information useful in the operation of thedevice.
 27. The catheter of claim 10, wherein the catheter furthercomprises a socket and wherein further said socket has an alignment pin,said shaft has an L-shaped channel for receiving said alignment pin andpreventing rotation of said shaft during axial insertion into saidsocket, said shaft having a flat region with said peripheral electricalcontact elements further arranged so as not to make electrical contactwith said socket contacts during said axial insertion and furtherarranged so as to make electrical contact with said socket electricalcontacts after the shaft is fully inserted and rotated when the pin isat the end of the elongated channel.
 28. The catheter of claim 10,wherein the catheter is configured to function as an oximeter probe.